The man was travelling as a passenger in a white Hyundai i10 Active which was travelling east along the A155 when it was involved in a collision with a tree at around 12.05pm yesterday (Sunday).
He and the driver of the vehicle, a woman in her 60s, were airlifted to hospital, but despite the best efforts of emergency services on the scene and hospital staff, the man died at 7.30pm that evening.
The woman remains in a serious condition.
The road was closed with diversions on the A155 between Revesby and East Kirkby while initial investigations were carried out.
A spokesman for Lincolnshire Police said: “We do not believe that there were no other vehicles involved, and we have now launched an investigation.
“We are now appealing for witnesses who may have seen the vehicle prior to the incident, or witnessed the collision itself to contact use. We are particularly keen to see any dashcam footage which may have captured the vehicle before the incident or the collision.”
If you can assist with the investigation, or have dash cam footage, please call Lincolnshire Police on 101, quoting incident 190 of January 30 or email [email protected]